This invention relates generally to the dental arts and more specifically to methods and compositions for treating and regenerating periodontal tissue.
The peridontium is the cushioning tissue which anchors the tooth root to the mandibular or maxillar jawbone tissue by suspending the tooth in the tooth socket ("alveolus"). Periodontal tissue includes both the periodontal ligament, a collagen-containing tissue that is in contact with the bone tissue, and cementum, a mineralized tissue that covers the dental root surface. These two hard tissues are connected through the periodontal ligament fibers that run in a perpendicular direction to the two surfaces and thereby serve to anchor and suspend the tooth in the tooth socket, providing a shock-absorptive cushion between the tooth and the jawbone that accommodates the pressure applied to teeth when food is being chewed.
Periodontal tissue loss may occur as a result of disease, including infectious diseases (e.g., gingivitis, caused by bacteria), nutritional diseases, e.g., scurvy, resulting from a vitamin deficiency, and a number of neoplastic diseases, including acute leukemia and lymphomas. The diseases are characterized by inflammation, bleeding and ulceration. Periodontal disease also may result from an opportunistic infection, e.g., in an immune-compromised individual. Left untreated, these diseases can cause significant periodontal tissue loss which loosen the tooth and ultimately can result in loss of the tooth and the alveolar bone tissue (periodontitis.) Chronic periodontitis is the primary cause of tooth loss in adults. Current treatments include professional cleaning to remove plaque and tartar, use of oral antiseptics, local and/or systemic antibiotic therapies, and/or surgical procedures to remove periodontal pockets formed from periodontal tissue lesions and necrosis. Typically, where a tooth has been lost as a result of periodontitis, a prosthetic tooth or removable bridge is substituted for the natural tooth.
Periodontal tissue loss also may occur as a result of mechanical injury to the tissue or to the tooth itself, particularly one causing tooth loss. Tooth loss also may occur as a result of any of a number of dental diseases, e.g., dental caries, pulpitis, or osteomyelitis.
A viable tooth can be reimplanted if implantation occurs quickly after loss, e.g., within thirty minutes, and if the periodontal tissue within the tooth socket is still healthy. However, if a significant period of time is allowed to elapse, the living periodontal tissue lining the tooth socket will be resorbed. In addition, the tooth itself begins to degenerate and a prosthetic tooth or removable bridge must be implanted. In the absence of healthy periodontal tissue the prosthetic implant is integrated directly into the jaw bone tissue in a condition called ankylosis (bone tissue in direct contact with dentin tissue.) The life of such prosthetic tooth implants often is limited due to the absence of viable periodontal tissue to enhance tooth anchoring and to absorb the impact of mastication on the prosthesis.
It is an object of this invention to provide a means for inhibiting periodontal tissue loss, as well as means for inducing regeneration of damaged periodontal tissue. Another object is to provide means for inhibiting the periodontal tissue damage and tooth loss associated with periodontal and other gum diseases. Yet another object is to enhance integration of an implanted tooth, including a reimplanted natural tooth or tooth prosthesis, in the tooth socket. Still another object is to promote periodontal tissue growth around an implanted tooth. Another object is to inhibit ankylosis of an implanted tooth or tooth prosthesis.
These and other objects and features of the invention will be obvious from the specification, drawings and claims, which follow.